EP apparatus, including EP copiers and EP printers, employ OPC coated drums and webs. While EP printers that employ OPC webs are generally arranged to enable replacement of the OPC web, EP printers which employ OPC-coated drums generally require the replacement of the entire drum assembly during the course of periodic maintenance.
U.S. Pat. No. 3,588,242 describes a drum structure which permits advancing of a photoconductor web positioned about the drum. The OPC web is stored in roll form on supply and take-up spindles within the interior of the drum. The photoconductor web extends from the supply role to the exterior of the drum, about the exterior periphery of the drum and then back into the interior of the drum to the take-up roll. To advance the OPC web, a length of OPC web is unrolled from the supply role (and taken up by the take-up role) such that a new length of OPC web is positioned about the periphery of the drum. In order to replace the OPC web, the drum must be disassembled and the internal supply and take-up rolls removed and replaced. Such action is not performable by the normal user and requires a maintenance call.
To maintain the cost of EP apparatus as low as possible, the industry trend has been to enable user-replacement of parts that are subject to wear. Presently, EP apparatus that employ drums are often provided with a replaceable toner cartridge which includes not only a replacement toner supply, but also an entirely new drum structure. Because the OPC coating on the drum has a shorter lifetime than the drum structure, replacement of the toner cartridge results in replacement of drum parts that have considerable useable life remaining.
Accordingly, it is an object of this invention to provide an EP apparatus with a user replaceable OPC web canister.
It is another object of this invention to provide a replaceable OPC-containing canister for an EP apparatus that employs a drum structure.
It is yet another object of this invention to provide an OPC-containing canister which is both simple and inexpensive in structure and is user-replaceable in a drum-containing EP apparatus.